Comparison of pain perception in children aged 6–16 years using computer-controlled local anaesthesia delivery (Dentapen®) versus conventional syringes: a randomised, split-mouth, crossover clinical trial

This study aimed to compare pain perception and physiological stress responses in children and adolescents (aged 6–16 years) receiving maxillary infiltration anaesthesia via Dentapen ® versus a conventional syringe. This study was a single-centre, randomised, split-mouth, crossover trial with 1:1 (AB/BA) allocation and a ≥ 1-week washout period. Participants requiring bilateral maxillary anaesthesia were enrolled. The primary outcome was self-reported pain using the Faces Pain Scale-Revised (FPS-R). Secondary outcomes included Visual Analogue Scale (VAS, ≥ 8 years), physiological stress measured by Galvanic Skin Response (GSR) and heart rate (HR), and behavioural response measured by the Sound, Eye, Motor (SEM) scale. FPS-R and SEM were analysed using Wilcoxon signed-rank tests; VAS, GSR, and HR using paired t-tests. Bonferroni correction (α = 0.0083) was applied for GSR/HR multiple comparisons. One-sided p-values reflect the directional superiority hypothesis that Dentapen ® would reduce pain and stress. Forty-seven participants were randomised; 30 completed both study periods (36% attrition). FPS-R scores showed a statistically favourable distribution with Dentapen ® compared with the conventional syringe (median paired difference 0.00 [− 2.00, 0.00]; Z = − 2.48, asymptotic one-sided p = 0.007; two-sided sensitivity p = 0.013). Fourteen of 30 participants had an FPS-R reduction of at least 2 points with Dentapen ® . Dentapen ® also produced lower galvanic skin response (GSR) at 0.6 mL (mean difference − 1.86 µS, raw one-sided p = 0.004) and 0.9 mL (mean difference − 1.65 µS, raw one-sided p = 0.004); both differences remained significant after Bonferroni correction (adjusted α = 0.0083). No significant differences were observed for VAS, heart rate, or SEM scores. Dentapen ® was associated with a statistically favourable distribution of FPS-R scores and lower GSR values during parts of anaesthetic deposition. However, the median paired FPS-R difference was zero, and no significant differences were observed for VAS, heart rate, or SEM. These findings suggest a possible benefit for some children, but the modest and heterogeneous clinical magnitude and study limitations preclude a definitive clinical recommendation. Larger prospectively registered trials are needed. ClinicalTrials.gov, TRN: NCT06785480; Registration date: 01 September 2025 (retrospectively registered).